"Mozilla today announced Boot to Gecko , a very ambitious project that aims to create a 'complete, standalone operating system for the open web'. This project's goal is to develop what seems like a ChromeOS-like operating system where all the apps are based on HTML5."

-Which means that lazy developpers are better writing web apps; even if they want afterwards to turn their work into a native app, they often can encapsulate it inside a java/C#/objective-C/etc. container.
(Of course, I am completely at odds with the weak, stretched argument exposed here: http://mattgemmell.com/2011/07/22/apps-vs-the-web/ )

-Ergo, B2G is THE reference platform of the future. This is not only a question of open-source zealotism. There is far more sense and strategy into it.